The embodiments described herein relate generally to rotating machines and, more particularly, to methods and apparatus for assembling turbine engines.
At least some known turbine engines include a plurality of rotating turbine blades or buckets that channel high-temperature combustion gas stream through gas turbine engines or channel high-temperature steam through steam turbine engines. Known buckets are typically coupled to a rotor within the turbine engine and cooperate with the rotor to form a turbine section. Moreover, these known buckets increase in radial length as a function of axial position on the rotor at least partially forming a divergent turbine hub on the rotor. At least some of the known gas turbine engines also include a plurality of rotating compressor blades that channel air through the gas turbine engine. These known compressor blades are typically coupled to the rotor and cooperate with the rotor to form a compressor section. Moreover, these known compressor blades decrease in radial length as a function of axial position on the rotor at least partially forming a divergent compressor hub on the rotor.
Many of these known turbine buckets and compressor blades include dovetail sections inserted into dovetail grooves defined within the rotor. Such dovetail grooves and inserted dovetail sections are typically assembled to form a plurality of rows. Each row of buckets defines a turbine stage and each row of blades defines a compressor stage. Both the turbine hub and the compressor hub include a predetermined extended length to facilitate axial installation and axial removal of the buckets and the blades, respectively. Such extended length increases an overall length and weight of the turbine section and the compressor section and increases capital costs of construction. Moreover, the increased weight of the turbine section and the compressor section may induce an increase in centrifugal forces acting on the rotor for a range of operational speeds. Such an increase in forces acting on the rotor may increase inspection and maintenance costs. Further, the increased weight may cause additional fuel usage to accelerate and maintain a speed of the rotor. Such an increase in fuel usage may increase operational costs.